1. Field of the Invention
The present invention relates generally to medical devices and methods. More particularly, the present invention relates to inter-luminal stents and anchors as well as catheters and methods for their deployment.
A number of inter-luminal endoscopic procedures require precise placement of tissue anchors or stents. For example, a number of procedures may be performed by entering the gastrointestinal (GI) tract through a first organ or structure, such as the esophagus, stomach, duodenum, small intestine, or large intestine, and delivering the anchor or stent to adjacent organs and structures such as the bile duct, the pancreatic duct, the gallbladder, the pancreas, cysts, pseudocysts, abscesses, and the like.
Such endoscopic procedures often require the delivery of a tissue anchor or stent to secure adjacent tissues or organs and optionally to provide an opening therebetween. Inter-luminal tissue anchors, typically referred to as stents when they include a central lumen, are used to enable fluid communication between adjacent ducts, organs or lumens. Often, precise placement of the tissue anchor or stent is necessary, especially when the tissue anchor or stent has well defined anchoring elements at the proximal and/or distal ends, the device is used to secure adjacent lumens, or the device is placed within a duct at a precise location and secured at the proximal and/or distal ends.
When deploying a stent or other tissue anchor between adjacent body lumens, organs, or other structures, it is typically necessary to penetrate a wall of both the first body lumen through which access is established and a wall of a second body lumen which is the target of the procedure. When initially forming such access penetrations, there is significant risk of leakage from either the access body lumen or organ. In some cases, such as when accessing the bile duct, loss of the body fluid into surrounding tissues and body cavities can present substantial risk to the patient. Thus, it would be desirable to be able to establish the initial penetrations needed to deploy a stent or anchor while minimizing the risk of body fluid leakage. The risk of body fluid leakage can be exacerbated when multiple catheters or other tools are needed for placement of the stent or other anchor. In particular, the need to exchange tools over a guidewire or through an access catheter can both prolong the procedure and increase the risk of body fluid leakage during the procedure.
Thus, it would be desirable to minimize both the time and the number of tools which are needed when endoscopically placing stents or other anchors between adjacent body lumens or organs.
It would be further desirable to provide catheters and access tools which are capable of being deployed from endoscopes to access adjacent body lumens or cavities while minimizing the risk of leakage. It would be particularly desirable to provide catheters and tools which include all elements and capabilities needed to both penetrate the luminal walls and place the stent or other anchor between said walls, thus eliminating the need to exchange tools during an access procedure. It would be still further desirable if such tools and access methods could continually apply tension on the luminal walls to maintain said walls in close apposition during the stent or other anchor placement, thus further reducing the risk of body fluid loss during the procedure prior to final deployment of the stent or other tissue anchor. At least some of these objectives will be met by the inventions described below.
2. Description of the Background Art
US2009/0281379 and US2009/0281557 describe stents and other tissue anchors of the type that can be deployed by the apparatus and methods of the present invention. The full disclosures of these publications are incorporated herein by reference. US 2003/069533 describes an endoscopic transduodenal biliary drainage system which is introduced through a penetration, made by a trans-orally advanced catheter having a needle which is advanced from the duodenum into the gallbladder. U.S. Pat. No. 6,620,122 describes a system for placing a self-expanding stent from the stomach into a pseudocyst using a needle and an endoscope. US 2005/0228413, commonly assigned with the present application, describes a tissue-penetrating device for endoscopy or endosonography-guided (ultrasonic) procedures where an anchor may be placed to form an anastomosis between body lumens, including the intestine, stomach, and gallbladder. See also U.S. Pat. No. 5,458,131; U.S. Pat. No. 5,495,851; U.S. Pat. No. 5,944,738; U.S. Pat. No. 6,007,522; U.S. Pat. No. 6,231,587; U.S. Pat. No. 6,655,386; U.S. Pat. No. 7,273,451; U.S. Pat. No. 7,309,341; US 2004/0243122; US 2004/0249985; US 2007/0123917; WO 2006/062996; EP 1314404 Kahaleh et al. (2006) Gastrointestinal Endoscopy 64:52-59; and Kwan et al. (2007) Gastrointestinal Endoscopy 66:582-586. Shaped balloons having differently sized segments and segments with staged opening pressures are described in U.S. Pat. Nos. 6,835,189; 6,488,653; 6,290,485; 6,022,359; 5,843,116; 5,620,457; 4,990,139; and 3,970,090.